view docs/man3/SDL_SetColors.3 @ 1258:b2283b0ded26

Date: Thu, 19 Jan 2006 20:02:29 +0200 From: Vassilis Virvilis <vasvir@iit.demokritos.gr> Subject: [SDL] Request: Please reconsider adding tag in SDL_Event Hi, Patch in question: --- include/SDL_events.h 20 Aug 2004 18:57:01 -0000 1.11 +++ include/SDL_events.h 19 Jan 2006 17:35:09 -0000 @@ -214,7 +214,7 @@ } SDL_SysWMEvent; /* General event structure */ -typedef union { +typedef union SDL_Event { Uint8 type; SDL_ActiveEvent active; SDL_KeyboardEvent key; Reasoning: ---------- 1) Allows forward declaration of the SDL_Event union in C++. Please note that in plain C it is possible to forward declare it. 2) Forward declaration is good because it allows encapsulation. It hides the specific implementation and does not necessarily exposes SDL staff to my appication's namespace 3) It can't harm plain C because tags are living in a different namespace than typenames 4) It is already done like this in other places in SDL. Check for example SDL_KeySym, and SDL_.*Event structures. 5) Right now I have to include SDL/event.h from a C++ header file. See 2)
author Sam Lantinga <slouken@libsdl.org>
date Fri, 20 Jan 2006 13:07:25 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_SetColors" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetColors\- Sets a portion of the colormap for the given 8-bit surface\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_SetColors\fP\fR(\fBSDL_Surface *surface, SDL_Color *colors, int firstcolor, int ncolors\fR);
.SH "DESCRIPTION"
.PP
Sets a portion of the colormap for the given 8-bit surface\&.
.PP
When \fBsurface\fR is the surface associated with the current display, the display colormap will be updated with the requested colors\&. If \fBSDL_HWPALETTE\fP was set in \fISDL_SetVideoMode\fR flags, \fBSDL_SetColors\fP will always return \fB1\fR, and the palette is guaranteed to be set the way you desire, even if the window colormap has to be warped or run under emulation\&.
.PP
The color components of a \fI\fBSDL_Color\fR\fR structure are 8-bits in size, giving you a total of 256^3 =16777216 colors\&.
.PP
Palettized (8-bit) screen surfaces with the \fBSDL_HWPALETTE\fP flag have two palettes, a logical palette that is used for mapping blits to/from the surface and a physical palette (that determines how the hardware will map the colors to the display)\&. \fBSDL_SetColors\fP modifies both palettes (if present), and is equivalent to calling \fISDL_SetPalette\fR with the \fBflags\fR set to \fB(SDL_LOGPAL | SDL_PHYSPAL)\fP\&.
.SH "RETURN VALUE"
.PP
If \fBsurface\fR is not a palettized surface, this function does nothing, returning \fB0\fR\&. If all of the colors were set as passed to \fBSDL_SetColors\fP, it will return \fB1\fR\&. If not all the color entries were set exactly as given, it will return \fB0\fR, and you should look at the surface palette to determine the actual color palette\&.
.SH "EXAMPLE"
.PP
.nf
\f(CW/* Create a display surface with a grayscale palette */
SDL_Surface *screen;
SDL_Color colors[256];
int i;
\&.
\&.
\&.
/* Fill colors with color information */
for(i=0;i<256;i++){
  colors[i]\&.r=i;
  colors[i]\&.g=i;
  colors[i]\&.b=i;
}

/* Create display */
screen=SDL_SetVideoMode(640, 480, 8, SDL_HWPALETTE);
if(!screen){
  printf("Couldn\&'t set video mode: %s
", SDL_GetError());
  exit(-1);
}

/* Set palette */
SDL_SetColors(screen, colors, 0, 256);
\&.
\&.
\&.
\&.\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_Color\fR\fR \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_SetPalette\fP\fR, \fI\fBSDL_SetVideoMode\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01